Numerical study on dispersion of fine settling particles in a depth dominated wetland flow

Abstract

Wetlands were long considered a nuisance because they were not suitable for growth of many agriculture products. Nowadays, owing to it’s importance in agriculture engineering, wetlands are invaluable to the mankind. Wetlands due to their commanding influences on ecosystem, benefited people and the environment in terms of water supply, climate regulation, biodiversity conservation and contaminant erosion are very useful in water resources. This investigation presents a numerical approach to detect the environmental dispersion of the fine particles with settling velocity in a wetland flow. A finite difference implicit scheme with layer-adapted mesh is employed to find the solution of the problem. The consequences of the various relevant parameters on the flow and concentration profiles are illustrated graphically. The computed concentration profiles agreed well with the existing experimental data as well as with the numerical solution. The vertical concentration profiles of fine settling particles are presented in different downstream stations with various settling velocities. It is found that the mixing of tracers into the wetland stream significantly influenced by settling velocity, dispersion time, damping factor, porosity, tortuosity, and mass dispersivity. This study finds great importance in understanding and organizing the elementary methods of wastewater treatment and flood damage control in natural and manufactured wetland flows.